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Alright, now I got sound again. One leg of Q2 was loose from the socket. Still sucks all the low end from the sound thou.

I measured all the connections both outside the board and inside it but didn't find anything wrong.. So next I think I'll quadruple check all values and components connections to board.

sry you were quicker 
can you post some pics? did you measure the connection to / from the board?
maybe some part got dead during soldering?
just some ideas

There's couple of pictures on the first post, but I'll take some more.

I don't believe that any component broke during soldering, I just quickly went through all the solders. But maybe the leads on the board itself? Need to measure.

I measured connections from the board and they are good.

Check. For a bridge, you said it was an etched board right? You may need to use a magnifier of some sort.

Yes, its an etched board. I'll try to check for any bridges! Don't think I have any kind of magnifier, but I'll do my best.

Oh god.. Started debugging this again today. I re-soldered everything on the board, because I thought there is another cold solder somewhere. Instead of getting it to work, I completely broke it. Now there's nothing on the output when the pedal is on. 

Starting to think that the problem is the low quality circuit board. There's something really strange going on.

make it true bypass or buffer

Sorry, badly worded.. It eats the low end when its on. Its true bypass and the bypass signal is good, but when I engage the effect it eats all low end. In other words, it works as high pass filter. 

The output volume is bit lower than the bypassed. I'll try it at band practice on saturday, but I'm guessing it needs some kind of booster / buffer after it.

Tested it today. Sadly, it doesn't work correctly. It eats all the low end from the signal - I didn't notice this at home because I used just my PC -speakers.. Any ideas?

Hah, removed the inductor and re-soldered - it works!  Cold solder, probably. Thanks a lot for all the suggestions!

The output volume is bit lower than the bypassed. I'll try it at band practice on saturday, but I'm guessing it needs some kind of booster / buffer after it. At least there's plenty of room for one. Any suggestions? 

Also still need to fiddle with the pot. Its kinda on the bright side currently.

Is the inductor in properly?


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At least it looks like it. I'll remove it tomorrow, measure it (just to be sure) and re-solder. 

Nope, it really doesn't do anything when the potentiometer is sweeped. Just same sound. Little bit of highs and lows missing and volume a bit lower than on bypass.

measure the resistance across the pot and between both pins. Check that it's actually changing the resistance.

Do you get ANY change in sound, even a tiny one when you sweep the pot?

Across the pot is 93 kOhm and between both pins the resistance is changing from about 0 Ohm to 80-90 kOhm. So the pot is working.

I don't hear any change in sound. I'm testing this with my computer and stereos because I have no guitar amps in house. But I think I'd still hear if there's anything going on.

Hey!

Little bit of backstory first: when I first got into pedal building in 2005 I ordered bunch of boards from a guy here in Finland. He etched these himself and they we're really cheap. Also the quality was a bit cheap. So, one of the boards I ordered was a Vox V847 -wah-wah replica from GeneralGuitarGadgets. I never got it to work (only bypass worked, no sound when it was on) and after some testing I just gave up.

A month back I found the board and decided to make it work. I re-wired everything and put it into a Crybaby enclosure. Hooked it up and it still doesn't work. Previously there was no sound, no there's sound but no effect. It basicly sounds like a wah that is left to "middle" position (=little bit of lows and highs are cut). The potentiometer doesn't seem to do anything.

Had to use Internet Archive to found these pictures, but here is the schematic and layout I used (thou I did the switch differently - so that the pcb input is grounded when its bypassed):
https://www.dropbox.com/s/q2q8gh4wuoxzc5y/wah_847_lo_tb.gif?dl=0
https://www.dropbox.com/s/70yf4nmjcqt12ur/wah_847_sc.gif?dl=0

And here's couple pictures of my build:
https://www.dropbox.com/s/9ucogx2jzqdsaxb/IMG_3997.JPG?dl=0
https://www.dropbox.com/s/nfdzu6k8mxqsd8c/IMG_3998_2.JPG?dl=0

And here's the voltages of the transistors:

Q1
C 4,14 V
B 0,69 V
E 0,12 V

Q2
C 9,03 V
B 3,72 V
E 3,29 V

I have triple checked all the capacitor and resistor values. They seem correct to me. I didn't have any MPSA18s so the transistors are BC550Cs.

Any ideas? This is currently driving me nuts. 

Edit. I just realized that those pictures are not that good (noisy). I'll take better ones tomorrow in daylight.

Found some 1 uF 100V Vishay caps but these are way too big to fit that board.

Oh well, made them fit..  Doesn't look good, but maybe I'll replace them with smaller ones later. Really have to stock up on my caps.



Edit. In that picture you can see how low I'm on caps.. Almost all are different types/manufacturers/voltage ratings.

Thanks! Exploding caps does not sound good.. I'm going through my random box right now. Found some 1 uF 100V Vishay caps but these are way too big to fit that board.

Also found some older box caps that are marked ".1K" on the top and "100" on the side. Are these 1uF 100V film caps or am I completely wrong?

Edit. Oh wait, these are probably 0.1 uF..

Hey!

I started to build two Kingslayers yesterday. Now all resistors and most of the caps are in their place, but I have little bit of shortage of some capacitors. I only have 1uF tantalums, nothing else. So, can I use those instead of film ones mentioned in BOM (C3, C11, C12, C17)? Which way should I put them in? I assume C11, C12 and C17 are there to block DC-current and C3 and the resistors R3 and R4 forms some kind of HP-filter for negative feedback?

My instinct says C11, C12 and C17 positive towards the op amps and C3 towards the input, but I dont trust myself enough.. 

Edit. Heres the link to the documentation: http://www.madbeanpedals.com/projects/Kingslayer/Kingslayer2.pdf

Looks great! I've been thinking about building one too. Current idea is to make it a flight case -type box where pedals are on the cover..

Thanks! Another kind of happy accident really. My initial plan was to spray the pedal white, add those stick-on letters, spray it all black, and then remove the letters to reveal the white underneath. Once I had sprayed a few coats of the flat black though, the letters looked nice and sealed, and I too liked how it looked, so I just left them on there. I don't think they're going anywhere now since the edges are buried under a good few coats of that black.

That really was a happy accident, because they look amazing! Have to consider something like this to some project too..